Intermediate clamp for contour seamer

ABSTRACT

A contour seamer for automatically stitching two or more plies of material together along a stitch line coextensive with and spaced from the aligned edges of the material plies is provided with a floating intermediate clamp which grips the material plies at their edges, maintaining them in proper alignment as the material is advanced.

Unite States Patent [191 Winlberg et al.

[ 51 Mar. 27, 1973 [54] INTERMEDIATE CLAMP FOR CONTOUR SEAMER [76] Inventors: Paul N. Winberg, 40 Villa Court,

Hempstead, 1 1550; Robert W. Winberg, 19 York Place, Williston Park, both of NY. 11596 [22] Filed: Nov. 24, 1971 [21] App1.No.: 201,767

[52] US. Cl ..112/l21.12 [51] Int. Cl. ..D05b 21/00 [58] FieldofSearch ..112/121.12, 121.11, 121.15,

[56] References Cited 7 UNITED STATES PATENTS 3,434,439 3/1969 Winberg ..1l2/l21.12

3,322,081 5/1967 Winberg ..l12/l21.l5

Primary Examiner-James R. Boler Attorney-Morton Amster et a1.

[57] ABSTRACT A contour seamer for automatically stitching two or more plies of material together along a stitch line coextensive with and spaced from the aligned edges of the material plies is provided with a floating intermediate clamp which grips the maten'al plies at their edges, maintaining them in proper alignment as the material is advanced.

7 Claims, 6 Drawing Figures INTERMEDIATE CLAMP FOR CONTOUR SEAMER This invention relates generally to sewing apparatus and in particular to an improvement in a machine for stitching multiple plies of material along a stitch line coextensive with and spaced from the aligned edges of the material plies. The presently preferred embodiment of the present invention disclosed herein is particularly adapted for use in the Material Stitching and Guiding Apparatus which is described in U. S. Pat. No. 3,434,439 of Mar. 25, 1969, the disclosure of which is hereby incorporated herein by reference.

The apparatus described in the prior patent is adapted to automatically guide one or more plies of material to the needle and feed dog of a conventional sewing machine so as to stitch said material along a stitch line coextensive with and spaced from the material edge. As described in the prior patent, the material is guided by a moving carriage or rabbit under control of sensing means adjacent the sewing needle and is adapted to follow the material edge regardless of whether the edge line is straight, angled or curved.

While the apparatus shown in the issued patent functions very well under most conditions, it has been found that for certain sewing applications and under certain circumstances, clamping of the work only at its leading end (by the sewing machine presser foot and feed dog) and at its trailing end (by the guide rabbit described in my prior patent) may be insufficient to achieve perfect coextensiveness of the aligned fabric edges as the fabric is advanced. Fabric misalignment may result in stitched-in pucker or other irregularities in the stitched seam which significantly degrade the quality of the finished product. While proper alignment could be achieved by pinning the fabric plies together at one or more locations along the desired seam prior to stitching, such pinning would be time consuming and would require removal of the intermediate pins as the work is advanced in process, interrupting the normal work flow.

It is thus an object of the present invention to provide an improved material stitching and guiding apparatus which assures proper alignment of several plies of material as the material is fed to a sewing machine. A further object of the invention is to insure proper material alignment in automatic stitching apparatus without additional operator setup and without operator intervention during the course of the stitching cycle.

In accomplishing these and other objects in accordance with the present invention, a machine for stitching multiple plies of material along a prescribed stitched line includes a main guide assembly engageable with said material contiguous to the trailing end thereof and operable to impart steering motion to the material. as it is advanced towards a stitching location and a floating auxiliary clamp which secures the multiple plies together in proper alignment as the material is advanced. The intermediate clamp is adapted to automatically preposition itself so as to grasp the material at a desired location along the aligned material edges when the work is positioned on the equipment and to release the material as the clamped point approaches the sewing machine feed dog.

Additional objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of a presently preferred but nonetheless illustrative embodiment of the present invention, when taken in conjunction with the appended drawings, wherein:

FIG. 1 is a plan view of the stitching and guiding apparatus and intermediate clamp;

FIG. 2 is a side elevation of the intermediate clamp assembly in its rest configuration;

FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. 2;

FIG. 4 is a plan view of the intermediate clamp assembly in its rest configuration;

FIG. 5 is a plan view of the intermediate clamp assembly at the commencement of its carriage return cycle; and

FIG. 6 is a schematic diagram of the control circuit for the auxiliary clamp.

The basic material stitching and guiding apparatus of the present invention is identical to that disclosed in U. S. Pat. No. 3,434,439 issued Mar. 25, 1969 and the disclosure of said patent (which is incorporated herein by reference) should be referred to for a better understanding of my basic apparatus. In the drawings and description that follow, portions of the original apparatus have been shown to establish the environment of my present improvement. For simplicity, the reference numerals used in the issued patent have been retained in this disclosure. Elements of the system which are new to the present invention are designated by numerals commencing with 202. This will assist the reader in integrating the disclosure of the issued patent with the present disclosure.

FIG. 1 shows the auxiliary clamping assembly generally designated 202 in position on the material stitching and gliding apparatus shown in the prior patent.

Broadly, the apparatus disclosed in the prior patent includes a table 14 supporting a conventional sewing machine 16 having a conventional feed dog arrangement for drawing material to be stitched past the sewing machine needle. In the system described in the prior patent, this feeding operation is aided by a conveyor including a series of feed belts 62, 64 and 66. In FIG. 1, the feed belts and conventional feed dog assemblies have been omitted for simplicity, but it is to be understood that our present invention contemplates possible use of these feeding techniques as well as others.

The basic guiding assembly includes an elongated straight and substantially rigid guide rail or track 88 which projects forward from the stitching location of the sewing machine and is intended to overlie table 14 and the upper courses of the belts of conveyor 60. The guide rail or track 88 is mounted for pivotal movement about a vertical pivot 92 in alignment with and rearwardly of the needle location of the sewing machine.

Guide rail 88 is suspended above the table 14 for side to side swinging movement about pivot 92 by an adjustable mounting arrangement which permits the rail to be laterally adjusted relative to the vertical pivot as described in my issued patent. As the work piece M is fed to sewing machine 16, rail 88 pivots about pivot 92 under control of photocells P1 and P2 (shown in my issued patent) to continuously reorientthe work piece so that machine 16 stitches a desired line parallel to and inwardly of the edge of the material.

As described in the prior patent, material plies M are held together at two locations first, at the needle location where the operation of the conventional feed dog and the inserted stitches secure the material plies together as the material is drawn toward the needle; second, at the trailing edge of the material where clamp member 120 mounted on a double arm clamp supporting lever 122 grasps the material plies for guiding and orienting the material as rail 88 pivots about point 92.

It has been found that under certain circumstances, clamping of the material plies at these two locations is insufficient to insure proper alignment of the coextensive material edges throughout the length of the edge being stitched. For example, where the garment being stitched requires that the various plies of material be cut to slightly different dimensions to provide fullness, or where certain materials and certain extreme seam curvatures are used, there is a tendency for the material plies to become misaligned along their edges, particularly in the region intermediate the feed dog and the clamping pin.

To overcome this problem, the system shown in FIG. 1 clamps the edges of the multiple plies of material M at a point intermediate the leading and trailing ends thereof by an intermediate clamp generally designated 210 carried by clamp carriage 206 which travels along an auxiliary guide rail 204 mounted parallel to and spaced from principal guide rail 88. As material M is fed to sewing machine 16 (with principal guide rabbit 110 riding on rail 88), clamp carriage 206' rides along auxiliary rail 204 with clamp 210 being pivotally mounted thereon so as to provide clamping force between the clamp jaws to maintain the plies of materia1 M in proper alignment without otherwise effecting the feeding motion of the material and without imparting any guiding or retarding forces to the material which would interfere with the proper flow of material as described in my prior patent. As the clamped point approaches the needle location, clamp 210 releases the material and is returned to its withdrawn position as described in more detail hereafter.

The auxiliary guide rail 204 is mounted parallel to rail 88 on strut 88a and rail support arm 212. Rail 204 is a T-shaped member as shown in cross-section in FIG. 3 and clamp carriage 206 rides on rail 204 by means of a series of guide rollers (shown in FIG. 3) including roller pairs 220 and 222 riding on the upper and lower faces, respectively, of rail 204; roller pairs 224 and 226 riding on the rearward face of rail 204; and roller pairs 216 and 218 riding on the forwardface of rail 204. All rollers have not been shown to simplify the drawings. This roller arrangement permits the carriage assembly to ride freely and smoothly along rail 204 in a constantly maintained orientation.

FIGS. 2 and 4 show the auxiliary clamp in its withdrawn or rest configuration, waiting for insertion of the material plies. The rearmost position of carriage 206 is established by adjusting the position along track 204 of clamp stop assembly 208 which includes a stop plate 254 mounted to be movable along rail 204 and to be secured at any desired location on rail 204 by locking knob 256. Stop assembly 208 is adjusted before commencement of the particular sewing operation (in a manner to be described hereafter) to secure carriage 206 so that clamp 210 is at its desired waiting position prior to insertion of the material plies. Once this initial adjustment is made, the sewing cycle can be repeated time after time with the readjustment of the stop and arm not being required until a new sewing operation is set up.

Clamp 210 comprises a lower fixed clamp arm 232 extending outwardly and downwardly from a clamp shaft 230 pivotally received in sleeve bearing 228. Arm 232 includes a clamping section 232a which extends horizontally and is adapted to be positioned beneath material M. Extending downwardly from arm 232 is a tab 232b which is secured by pivot 236 to tab 234b extending downwardly from arm 234. Tab 234a pivotally secures arm 234 to the rod of cylinder C3 at pivot 240. The opening and closing of clamp 210 is controlled by cylinder C3 which is mounted at its other end to an upward extending tab 232a on fixed clamp member 232. The entire clamp assembly including cylinder C3 is frictionally secured to clamp shaft 230. As will be seen in FIG. 3, clamp shaft 230 extends through sleeve bearing 228 and thereafter through washer 229 fixed to shaft 230, friction disc 248, the fixed clamp member 232, spring 246, washer 244 and nut 242. Spring 246 tenses the fixed clamp member 232 against friction disc 248 so that as clamp shaft 230 rotates freely in sleeve bearing 228, clamp 210 will pivot in rigid relation with the shaft. At the same time, with clamp shaft 230 held rigidly (as described below), clamp 210 can be rotated against the friction of disc 248 to any desired position once the shaft is released. This feature permits clamp 210 to be preset to assure a desired angled orientation when carriage 206 is in its retracted position so that, after completion of a sewing cycle, the arm will automatically resume the desired start position.

In the rest position, waiting for insertion of material (as shown in FIGS. 1, 2 and 4) carriage 214 is held by latch 258 which is pivoted from pivot 260 on plate 254 and is urged by spring 261 acting against pins 264 and 266 in a counterclockwise direction against stop 262. The hook portion 258a of latch 258 engages pin 268 which extends outwardly from the carriage plate 214. An air cylinder Cl is supported by brace 280 in plate 254, with the shaft of air cylinder Cl carrying a cam plate 270 which includes a rearwardly extending tail section 270a having an escapement element 272 pivoted at pivot 274. Escapement element 272 is tensed by spring 276 against stop 278 so that at the commencement of the stitching cycle, the shaft of cylinder Cl (which is extended at rest) withdraws driving escapement element 272 against the upper projecting portion of latch 258, disengaging hook 258a from pin 268. On disengagement, carriage assembly 206 is immediately separated from stop assembly 208 by the action of spring 296 (which cooperates in an obvious manner with support posts 298 extending outwardly from the rear face of plate 254 and with slidable shaft 300 inserted through apertures in posts 298 and having a stop plate 304) to drive engagement plate 302 on the forward end of shaft 300 against the rear of carriage 206. It will also be appreciated that, as the carriage retracts (in a manner described below), shaft 300 is driven rearwardly, tensing spring 296 which remains tensed when hook 258a locks pin 268. The spring thus acts both as a catch spring when the carriage retracts and to separate the carriage and stop assemblies at the start of a sewing cycle.

To establish the desired position of clamp 210 at rest, cylinder C1 carries a cam plate 270 which operates in conjunction with a pivot arm 282 rigidly secured to clamp shaft 230 to establish the position of the clamp shaft when the carriage is in its withdrawn position. Specifically, the clamp shaft extends upwardly and is rigidly connected to pivot arm 282 which carries a follower roller .284 pivoted at 286. The shaft of cylinder C1 carries cam plate 270 including a cam surface 270b and a seat portion 270C adapted to receive follower roller 284. When carriage 206 is withdrawn to its rearmost position latched to the stop, the shaft of cylinder C1 is extended with cam track 27012 engaging follower roller 284, pivoting arm 282 and clamp 210 outwardly until follower roller 284 is received in seat 270c. The position of the clamp is frictionally preset so that when the follower roller 284 is received in seat 270e, clamp 210 is in the desired position. Because of the length of the shaft of cylinder C1 and the necessity for cam track 2701: to exert force to guide follower roller 284, the cam plate 270 includes a depending guide roller 292 which is adapted to be received in an upstanding guide track 290 on the carriage. When the shaft of cylinder C1 extends, roller 292 is received within track 290 and the engagement of the roller 292 on the interior walls of the track 290 tends to prevent lateral displacement of the cylinder shaft and cam track as it engages the follower roller 284.

Once the carriage is released and clamp 210 is secured to the material stack, the carriage is free to travel along rail 204 and clamp 210 is free to pivot with clamp shaft 230 in sleeve bearing 228 so that the clamp exerts substantially no force on the goods in the horizontal plane which would tend to interfere with the normal operation of the feed system as described in the prior issued patent.

As carriage assembly 206 approaches the forward most end of rail 204 (i.e. as the grip portion of clamp 210 approaches the needle location on sewing machine 16), surface 214a on the carriage engages arm 294' of switch SW1, depressing the switch and initiating a retract cycle which will be described in more detail in conjunction with FIG. 6. During the retract and reposition cycle, clamp 210 releases the work and the shaft of cylinder C2,mounted on the forward end of rail 204, extends against cushion 288, driving the carriage as sembly in a rearward direction along the rail into latching engagement with stop 208 as described above. During this rearward travel, clamp 210 pivots inwardly toward rail 204 under urging of return spring 252 (shown in FIGS. 3 and 5) on the clamp shaft. This insures that the clamp does not interfere with the material M in process. Once the carriage is retracted and latched as described above, cylinder C1 drives cam track 270 outwardly, reestablishing the start position of the clamp as previously described.

The operation of my system will now be described in conjunction with the schematic diagram of FIG. 6. It should be understood that cylinders C1, C2 and C3 are all spring biased so that the cylinder shafts are withdrawn automatically under urging of an internal spring when no air pressure is applied to the cylinder. The cylinders C1, C2 and C3 are controlled by a series of solenoids S1, S2 and S3 which are current actuated. In all cases, when current is applied to the solenoid, air passages P1, P2 and P3 are open and air is applied to the cylinder extending the cylinder shaft. When the current flow is terminated, the shafts of cylinders C1, C2 and C3 return to their withdrawn position.

FIG. 6 shows the control circuit for this system at its rest state as shown in FIGS. 1, 2 and 4. The stitching cycle is commenced by the operator operating foot switch SW3 which momentarily closes contacts SW31 and momentarily opens contacts SW32. Closing of contacts SW31 applies current from across a conventional current line (shown as the upper and lower parts in FIG. 6, it being understood that any closed circuit between these paths sends current to flow in that closed circuit) along a path through contacts SW31 through the coil of relay R3 to the other electrical side of the system. This application of current to relay R3 closes relay contact pairs R31 and R32 with pair R31 operating as a latch (in a manner to be described hereinafter) so that, once current has been applied to relay R3, the relay remains latched until the circuit including relay contacts R31 is opened. Relay contact R32 closes current across solenoid S3 of cylinder C3. As described above, the application of such current applies air to cylinder C3, thereby driving the shaft of cylinder C3 outwardly and clamping the goods in the desired position. This clamping action maintains the alignment of the goods until released.

At the same time, the momentary openings of contacts SW32 removes current from the coil of R2 (which had been under current and closed while the apparatus is at rest through a current path from the high side of the circuit through SW32 through the latching contacts R22 on relay R2) and relay contacts R21, R22 and R23 open. The opening of contacts R23 removes current from solenoid S2 and the shaft of cylinder C2 withdraws by action of its internal spring, readying C2 for initiation of the return phase of the sewing cycle.

Having clamped the goods and returned C2, foot switch SW3 is released, the goods remaining clamped by virtue of the latching operation of contact R31. The operator next initiates the stitching cycle by depressing foot switch F82 in accordance with the description of FIG. 3 in the above-identified patent. In accordance with ourpresent invention, switch F82 is engaged with switch contacts SWZ which are opened when the switch is activated. The opening of the contact SWZ opens the circuit to time delay relay R1 which is normally closed when at rest. The release of this relay opens relay contacts R12 which removes the current flow from solenoid S1, removing the air pressure from cylinder C1, permitting cylinder C1 to withdraw, releasing the latch mechanism which was previously holding the carriage in place and withdrawing cam plate 270. At the same time, FS2 commences the stitching cycle as described in my prior application.

The release of current to relay R1 closes the make before break contact R11 to the right hand contact and, thereafter, breaks the left hand contact. Relay R1 is thus arranged to receive current through contacts R21 and switch SW1. The carriage 206 is then drawn toward sewing machine 16 until plate 214a engages arm 294 of switch SW1, driving switch SW1 from its normal right hand rest position to its depressed position (left hand position in FIG. 6). At this time, switch SW1 opens the current path through R31 to the coil of relay R3 and relay R3 releases, opening R32 which removes current from solenoid S3, opening the jaws of clamp 210. When SW1 closes to its left hand contact (in FIG. 6), it closes a path from the high side of the electrical circuit to the coil of relay R2 closing contacts R23 and applying current to S2, driving the shaft of C2 outwardly against pad 288 on the carriage and driving the carriage rearwardly. As soon as the carriage retracts, switch SW1 returns to its right hand rest position. However, relay R2 is self latched and remains closed through a path from the high side of the circuit through SW32, through R22 and the coil of R2.

The closing of relay R2 by switch SW1 closes contacts R21 which applies current from SW1 through R21 through R11 to the time delay relay R1 and later through SW32, R22 and R21. At a prescribed time after this application of current to the coil of R1, R1 closes contacts R12, activating solenoid S1 and extending the cam plate 270 to reposition the clamp for commencement of a new cycle. R1 also closes contacts R1 1 to its left side contact (in FIG. 6) and, thereafter, opens the right side contact of R11 so that relay R1 is under current from some source at all times. The repositioning of contact R11 is the final step in returning the system to its ready waiting configuration with the clamp extended to a desired position ready to receive a new series of material plies for another stitching cycle.

The above described arrangements are merely examples of the application of the principles of the present invention. Other embodiments will be obvious to those skilled in the art without departing from the spirit and scope of the present invention or defined in the following claims.

I claim:

1. Apparatus for stitching multiple sheets of material together along a prescribed stitch line in relation to the aligned edges thereof comprising a support, sewing mechanisms on said support operable at a stitching location for successively stitching said material along said prescribed stitch line, said material being arranged forwardly of said stitching location and advanced toward and through said stitching location along a normal feed path relative to said needle, main guide means engageable with said material and operable to impart steering motion to said material as the same is advanced toward said stitching location for displacing said material relative to said normal feed path such that said material will be stitched substantially along said stitch line, said guide means being engageable with said material adjacent the trailing end of said aligned edges, means responsive to deviations of said edges relative to said normal feed path for moving said guide means in a direction to restore said edge, said guide means being effective to impart steering motions to said material as it moves toward said stitching location to continuously orient and properly present said material in relation to said sewing mechanisms, and auxiliary clamping means engageable with said material adjacent said aligned edges for maintaining said edges in proper alignment as the same is advanced toward said stitching location, said clamping means being movable with said main guide means so as to maintain said proper edge alignment without interfering with said steering motions.

2. A machine according to claim 1 wherein said auxiliary guide means is located and arranged to engage said materialat an intermediate location of said edge.

3. A machine according to claim 2 wherein said main guide means includes an elongated movable main guide rail and said auxiliary clamping means includes an elongated auxiliary guide rail mounted for movement with said main guide rail and an auxiliary material clamp movably mounted on and guided by said auxiliary guide rail and movable toward said stitching location as said material is moved under the influence of said sewing mechanisms.

4. A machine according to claim 3 including an adjustable clamp-positioning stop on said auxiliary guide rail for establishing a starting position for said auxiliary material clamp along said auxiliary guide rail.

5. A machine according to claim 1 including means operable in response to the approach of said auxiliary clamping means to said stitching location for disengaging the same from said material.

6. A machine according to claim 5 including means operable after said auxiliary guide means is disengaged from said material for automatically restoring said auxiliary guide means to a starting position removed from said stitching location.

7. A machine according to claim 6 wherein said auxiliary guide means includes a movable material clamp and an adjustable stop engaging said material clamp when the same is restored to said starting position. 

1. Apparatus for stitching multiple sheets of material together along a prescribed stitch line in relation to the aligned edges thereof comprising a support, sewing mechanisms on said support operable at a stitching location for successively stitching said material along said prescribed stitch line, said material being arranged forwardly of said stitching location and advanced toward and through said stitching location along a normal feed path relative to said needle, main guide means engageable with said material and operable to impart steering motion to said material as the same is advanced toward said stitching location for displacing said material relative to said normal feed path such that said material will be stitched substantially along said stitch line, said guide means being engagEable with said material adjacent the trailing end of said aligned edges, means responsive to deviations of said edges relative to said normal feed path for moving said guide means in a direction to restore said edge, said guide means being effective to impart steering motions to said material as it moves toward said stitching location to continuously orient and properly present said material in relation to said sewing mechanisms, and auxiliary clamping means engageable with said material adjacent said aligned edges for maintaining said edges in proper alignment as the same is advanced toward said stitching location, said clamping means being movable with said main guide means so as to maintain said proper edge alignment without interfering with said steering motions.
 2. A machine according to claim 1 wherein said auxiliary guide means is located and arranged to engage said material at an intermediate location of said edge.
 3. A machine according to claim 2 wherein said main guide means includes an elongated movable main guide rail and said auxiliary clamping means includes an elongated auxiliary guide rail mounted for movement with said main guide rail and an auxiliary material clamp movably mounted on and guided by said auxiliary guide rail and movable toward said stitching location as said material is moved under the influence of said sewing mechanisms.
 4. A machine according to claim 3 including an adjustable clamp-positioning stop on said auxiliary guide rail for establishing a starting position for said auxiliary material clamp along said auxiliary guide rail.
 5. A machine according to claim 1 including means operable in response to the approach of said auxiliary clamping means to said stitching location for disengaging the same from said material.
 6. A machine according to claim 5 including means operable after said auxiliary guide means is disengaged from said material for automatically restoring said auxiliary guide means to a starting position removed from said stitching location.
 7. A machine according to claim 6 wherein said auxiliary guide means includes a movable material clamp and an adjustable stop engaging said material clamp when the same is restored to said starting position. 